Improvement in punching-machines



' J. L. PEARSON. Punching-Machine.

No. 215,663. Patented May 20,1879.

Maw

UNITED STATES PATENT OFFICE.

JACOB L. PEARSON, OF CHESTER, PENNSYLVANIA, ASSIGNOB OF ONE-HALF HISRIGHT TO JOHN HUESTON, OF SAME PLACE.

IMPROVEMENT IN PUNCHlNG-MACHINES.

Specification forming part of Letters Patent No. 215,663, dated May 20,1879; application filed February 15, 1879.

To all whom it may concern.-

Be it known that I, J AGOB L. PEARSON, of Chester, Delaware county,Pennsylvania, have invented a new and useful Improvement inPunching-Machines, of which invention the following is a specification.

The punch herein described is designed for punching iron ship-plates andboiler-plates, and for forming the eountersinks therein for therivet-heads, at one operation of the punch.

In the drawings, Figure 1 is a side elevation of the punch. Fig. 2 is alower-end view of the same. Fig. 3 is a side elevation of an ordinarymulching-machine, showing my said punch in its proper working position.Fig. 4 is a longitudinal section of the punch and a cross-section of theholding plate or guide g on the line y y of Fig. 5 and Fig. 5 is atransverse section of the same on the line as w of Fig. 4, showing, inaddition, the forks of the foot h. p I

Referring to Fig. 1, it will be seen that the lower or penetrating end,a, of the punch is of the ordinary solid cylindrical form. 0 cc 0 0 care tapered cutters formed around the punch, as shown, three-eighths (g)of an inch (more or less) from the face of the penetrating end a of thepunch, according to the thickness of the iron plates on which the punchis intended to be used. The office of the cutters c is to form acountersink for a rivet-head with each hole punched.

d and e are screw-threads formed on the shoulder f of the punch, asshown. 9, Figs. 4 and 5, is a holding plate or guide, which is providedwith screw-threads corresponding to those on the shoulder f. This guideis located in the forks of the foot h, (see Figs. 3 and 5,) which isemployed in all punching-machii'ies to keep the iron plates from risingup with the punch as the latter is drawn up after a hole has beenformed.

i and j, Fig. 3, are plates, one being above and the other below theforks of the foot h, for holding the guide gin its place, these platesbeing secured together by means of bolts passed through bolt-holes madein them and in the guide 9 for the purpose.

The slot k, Fig. 1, for the holding-pin m is lengthened and deepened ascompared with the corresponding slotin ordinary punches. This is for thepurpose of allowing the punch to turn in its socket.

When the machine is put in operation, the

punch descends with a partially rotary movement, caused by thescrew-threads d 0 working in the corresponding screw -threads of theguide g, and as soon as the penetrating end of the punch has forced thewad or punching out of the plate the cutters a come into operation,forming in the plate the countersink for the rivet-head.

The extent of the longitudinal movement of the punch is defined by thedistance between the face of the penetrating end of the punch and thetop of the cutters 0, so that the screwthreads (I 0 never disconnectthemselves from the corresponding threads in the guide g.

I do not confine myself to the use of the two screw-threads d e, as asingle broad thread,

which equals in strength the two threadsshown, answers the purposeequally well, the corresponding change being made in the screw-threadsof the guide g.

I claim The combination of the punch constructed with the cutters c, thescrew thread or threads on the shoulder f, the guide 9 and the foot h ofa punching-machine, for forming the countersink in the plate in the samemovement by which the plate is punched, substantially as set forth.

JACOB L. PEARSON.

Witnesses:

J. E. SHAW, BENJ. B. WELSER.

